Frangible projectile

ABSTRACT

A projectile intended to be incorporated in a cartridge for firing from a shotgun, for use by police forces and other law enforcement agencies as a means of rapidly breaking a lock or bolt holding a door closed, comprises a cylindrical low-strength casing, for example of paper, filled with a dense non-toxic finely divided material such as tungsten powder. An advantage of the projectile disclosed, as compared to conventional shotgun projectiles, is that whilst the projectile will retain its integrity until it strikes the target and thus will effectively blast a hole through a lock or bolt or through the portion of the door carrying such, the impact of the projectile with the target will fragment the paper casing allowing the tungsten powder to disperse rapidly so that after the powder has passed through the door against which the projectile is fired the powder will lose momentum within a very short distance due to atmospheric drag on the fine tungsten particles.

[0001] It is an object of the present invention to provide a frangible projectile which can be readily and cheaply manufactured and which is particularly suitable for use by police forces or other law enforcement agencies as a short range projectile for destroying door locks or bolts to secure rapid forced entry to premises.

[0002] According to the invention there is provided a frangible projectile comprising a closed low-strength case containing a charge of finely divided dense particles.

[0003] In a preferred embodiment, the case is made of paper and the dense particles comprise tungsten powder. In this preferred embodiment, not only does the tungsten have the advantage of high density, but it has also the significant advantage, as compared with lead, for example, of being non-toxic. Accordingly use of frangible projectiles in accordance with the preferred embodiment, poses less of a health hazard for police officers or other law enforcement personnel, in the course of practice and training in the use of such projectiles and less of a health hazard for them or for other parties involved in incidents where such projectiles may be used in earnest, whether criminals or innocent third parties. Likewise, premises where frangible projectiles in accordance with the preferred embodiment are used are not contaminated with dispersed particles of toxic metal.

[0004] An embodiment of the invention is described below by way of example with reference to the accompanying drawings in which:

[0005]FIGS. 1 and 2 are perspective views from opposite ends of the frangible projectile embodying the invention;

[0006]FIG. 3 is a view in axial section of the projectile, and

[0007]FIG. 4 is a view in axial section of a cartridge incorporating the projectile.

[0008] The projectile 10 illustrated is intended to be fired from a large-bore, smooth-bore firearm such as a shotgun and comprises a cylindrical casing of an external diameter appropriate to the bore of the firearm. The casing may, for example, be formed as a rolled paper tube 12 having the tube wall folded over across the diameter at one end to form a casing base 30. The interior of the casing is filled with a high density powdered granular material, such as tungsten powder, indicated at 32 in FIG. 3, which is contained within the casing by a closure disc 34 fitting snugly within the casing at its upper end, the disc being retained by folding or rolling over the upper edge of the tube, above the disc 34, inwardly onto the top of the disc 34 around the periphery thereof, as illustrated in FIG. 3, in much the same manner as was customary for paper tube cartridges before these became almost universally replaced by plastics equivalents. Of course, the casing 12 of the projectile may be made in any convenient manner, although paper is the preferred material. Thus, for example, the tubular casing 12, after being filled with tungsten powder, can be closed at the upper end in the same way as it is closed at the lower, or both the upper and lower end could be closed by cardboard discs like the disc 34 retained by rolling over the edge of the tube onto the outer surface of the discs.

[0009] The projectile may be incorporated in a cartridge, as illustrated schematically, partly in side elevation and partly in axial section, in FIG. 4, in which reference 38 indicates the tubular body of the cartridge proper, the projectile being illustrated as being accommodated within the front end of the cartridge which in turn is closed at its front end by a closure disc 40 retained within the front end of the cartridge tube 38 and retaining, within the cartridge, the projectile, a wad 42 behind the projectile and an explosive charge 44 behind the wad. The cartridge, apart from the projectile 10, is conventional.

[0010] The cartridge incorporating the projectile 10 is intended primarily for use by police forces and other law enforcement agencies as a means of rapidly breaking a lock or bolt holding a door closed, the main advantage of the projectile disclosed, as compared to more conventional projectiles in this context, being that whilst the projectile will retain its integrity until it strikes the target and thus will effectively blast a hole through a lock or bolt or through the portion of the door carrying such, the impact of the projectile with the target will fragment the paper casing allowing the tungsten powder to disperse rapidly so that after the powder has passed through the door against which the projectile was deployed, the tungsten powder rapidly loses much of its momentum, through atmospheric drag, within a very short range and is thus less likely than conventional projectiles to cause personal injury or structural damage to persons or equipment within the premises to which entry is being effected. A further advantage, where tungsten powder is used, is that tungsten powder is non-toxic, unlike lead powder, for example, so that police officers or other personnel undergoing training or practice in the use of the frangible projectiles do not run the risk of inadvertently ingesting, e.g. by breathing, particles of toxic metal which might build up, over time, in their bodies.

[0011] It will be appreciated that other dense particles, apart from tungsten powder, may be used. However, tungsten is preferred because of its density and non-toxicity, and, for the specific purpose referred to above, finely divided powder is preferred in order to minimise the effective range of the contents of the projectile casing beyond the target at which it is fired. 

1. A frangible projectile comprising a closed low-strength case containing a charge of finely divided dense particles.
 2. A projectile according to claim 1 wherein the case is made of paper.
 3. A projectile according to claim I wherein the dense particles comprise tungsten powder.
 4. A cartridge, comprising a hollow tubular outer body, a propellant charge within the hollow tubular outer body, a wad within the hollow tubular outer body in front of the propellant charge, a projectile according to claim 1 being accommodated within the hollow tubular outer body in front of the wad, and closure means at the front end of the hollow tubular body. 